RU2023523C1 - Method of hollow pieces drawing from sheet type metal - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: method provides for reduction of ingot initial diameter, that is accompanied with pre-planned blank flange crimping and ironing by required for crimping effort of punch and required for ironing effort of vibrating pressing mechanism. Preliminary drawing of piece is exercised without reduction of initial diameter of blank by blank flange rolling up to formation of variable thickness, rule of variation of which is determined according to dependance:

, with S_o-initial thickness of blank; S_тh - current thickness of blank flange on D_тh diameter; D_out - outer diameter of drawing piece; D_тh - current diameter of blank flange, on which S_тh thickness is made. Then piece drawing is exercised to reduce flange diameter with preservation of given rule of its thickness change. EFFECT: method is used for pieces drawing from sheet type metal. 4 dwg

Description

 The invention relates to the processing of metals by pressure, namely to sheet stamping, and is intended for the manufacture of hollow products from sheet metal.

 A known method of drawing hollow sheet metal products, in which the hood is accompanied by deliberate corrugation and smoothing of the flange part of the workpiece by acting on the central part of the workpiece by the pull force of the punch and on the flange part by force from the clamping side, making reciprocating movements (pulsating) along the axis of the punch [1].

 The disadvantage of this method is that the natural thickening of the flange of the workpiece during drawing makes it difficult to corrugate the flange and thereby limits the technological capabilities of the process.

 There is also known a method of drawing hollow articles, in which the deliberate corrugation and smoothing of the flange is carried out simultaneously with a circular oscillation of the clamp with a conical working surface [2].

 The disadvantage of this technical solution is that the drawing method is carried out with a substantially constant thickness of the workpiece flange equal to its original thickness.

 The purpose of the invention is the expansion of technological capabilities for the manufacture of hollow products by reducing the effort spent on the corrugation of the flange.

, (1) где S_o - исходная толщина заготовки;
S_т - текущая толщина фланца заготовки на диаметре D_т;
D_и - наружный диаметр вытягиваемого изделия;
D_т - текущий диаметр фланца заготовки, на котором устанавливают толщину S_т, после чего вытяжку изделия осуществлять с сокращением диаметра фланца при соблюдении заданного закона изменения толщины фланца.This is achieved by the fact that in the method of drawing hollow products from sheet metal, in which the reduction in the initial diameter of the workpiece is accompanied by deliberate corrugation and smoothing of the workpiece flange by acting on the central part of the workpiece with the force from the punch side required for drawing and corrugation, and on the workpiece flange by force From the side of the oscillating clamp, which is necessary for smoothing it, it is proposed to pre-stretch the product without reducing the initial diameter of the workpiece by rolling the fl gloss preform up to the formation therein of varying thickness, wherein the variation depending on the adopted:
S _t = S

, (1) where S _o is the initial thickness of the workpiece;
S _t - the current thickness of the workpiece flange on a diameter of D _t ;
D _and - the outer diameter of the product being drawn;
D _t - the current diameter of the workpiece flange, on which the thickness S _{t is set} , after which the product is drawn out with a reduction in the diameter of the flange, subject to the given law of changing the thickness of the flange.

 In FIG. 1 shows the initial position of the device for drawing according to the proposed method; in FIG. 2 - corrugation and smoothing of the flange during preliminary drawing without reducing the initial diameter of the workpiece; in FIG. 3 - an intermediate stage of drawing the product with a reduction in the diameter of the blank flange; in FIG. 4 is a graph of the variation in thickness of a workpiece flange after preliminary drawing.

 A device for implementing the proposed method of drawing contains a punch 1, a matrix 2 placed with a matrix holder 3, a clamp 4, the latter being installed in the carrier 5, which interacts with its spherical surface 6 with the corresponding spherical surface of the support 7.

 The axis of the oscillating carrier 5 and clamp 4 is inclined to the axis of the device at an angle α.

 Position 8 is assigned to the initial workpiece, 9 to the workpiece on the preliminary hood, and 10 to the workpiece at the stage of drawing with reduction of the workpiece flange.

 The proposed method of drawing is as follows.

 In the initial position, the upper part of the device, including the punch 1, clamp 4, carrier 5 and support 6, are in the highest position (see Fig. 1).

 When the press is turned on, the punch 1 is lowered with the clamp 4 until it comes into contact with the workpiece 8, after which both the working stroke of the punch 1 (the force from which is created sufficient to corrugate the workpiece flange) and the oscillating clamp 4 working stroke (the force from which is created are required to smooth the workpiece flange).

,, где S_т - текущая толщина заготовки; D_и - наружный диаметр вытягиваемого изделия; D_т - текущий диаметр заготовки, на котором устанавливают толщину S_т.As a result of this, the preform is first drawn out without reducing its initial diameter D _o when the initial preform thickness S _o changes to a variable thickness S _t , the law of change of which is presented according to the dependence S _t = S

,, where S _t - the current thickness of the workpiece; D _and - the outer diameter of the product being drawn; D _t - the current diameter of the workpiece, which set the thickness S _t

It should be noted that rolling the workpiece flange according to a given law of thickness variation S _{t is} accompanied by the outflow of metal in the radial direction to the exhaust hole of the matrix. This, along with the deliberate corrugation of the workpiece flange, contributes to the intensification of the preliminary drawing process to form a steady-state variable thickness S _t in the workpiece flange.

= S_o/

(где К_о = D_o/D_и - коэффициент вытяжки детали), и по мере сокращения диаметра D_т с D_o до диаметра вытяжного отверстия матрицы D_и за счет естественного утолщения фланец в конце вытяжки (при D_т = D_и) получит толщину S_о.The end of rolling the flange of the workpiece 9 to a predetermined law of change in thickness S _{t is} characterized by the fact that the surface 11 of the oscillating clamp 4 abuts against the surface 12 of the matrix 2, after which the preliminary hood passes into the hood with a reduction in the initial diameter of the workpiece D _о to the required diameter D _t (see Fig. 3) while maintaining a variable gap between the clamp 4 and the matrix 2 according to the above law, moreover, at this stage of the drawing, the thickness of the workpiece S _t with a diameter D _t = D _o will be equal to S _t = S

= S _o /

(where K _o = D _o / D _and is the coefficient of drawing of the part), and as the diameter D _t with D _o decreases to the diameter of the exhaust hole of the matrix D _and due to natural thickening, the flange at the end of the hood (with D _t = D _and ) will receive thickness S _about .

 After the product is drawn out, the punch 1 and the clamp 4 are raised to their highest position, and the stamped product is removed from the punch and removed from the working area of the device. As a result, the device is ready for drawing the next hollow article.

=S_o/

. Так например, при K_o = 4 имеем S_т=S_o/

=S_o/2= 0,5S_o т.е. толщина кромки заготовки будет в 2 раза меньше исходной толщины S_o. Учитывая, что усилие со стороны пуансона, затрачиваемое на гофрирование фланца заготовки, зависит от текущей толщины S_т в квадрате (от S_т ²), то в рассматриваемом случае это усилие будет в 4 раза меньше, чем усилие при вытяжке по прототипу, и в 16 раз меньше, чем при вытяжке по аналогу. Этим создаются условия для расширения технологических возможностей предлагаемого способа вытяжки: увеличивается глубина вытягиваемых изделий; обеспечивается изготовление деталей с большей относительной толщиной изделия; снижается усилие для разглаживания фланца заготовки; обеспечивается высокое качество изготавливаемой продукции и т.п.Due to the fact that the preliminary drawing is carried out without changing the initial diameter of the workpiece D _o , rolling of the flange of the workpiece takes place when lowering the oscillating clamp 4 until the surfaces 11 and 12 are closed, it reduces the initial thickness S _o to the thickness S _t = S on the outer diameter of the workpiece

= S _o /

. So for example, when K _o = 4 we have S _t = S _o /

= S _o / 2 = 0.5S _o i.e. the thickness of the edge of the workpiece will be 2 times less than the initial thickness S _o . Considering that the force on the side of the punch spent on corrugating the flange of the workpiece depends on the current thickness S _t squared (on S _t ² ), then in this case this force will be 4 times less than the force when drawing according to the prototype, and 16 times less than with an extract by analogy. This creates the conditions for expanding the technological capabilities of the proposed method of drawing: increases the depth of the drawn products; production of parts with a greater relative thickness of the product is ensured; effort to smooth the workpiece flange is reduced; high quality of manufactured products, etc. is ensured.

=

=

=335 мм
Текущая толщина S_т во фланцевой части заготовки устанавливается согласно формуле (1):
S_т=S

=2

и при D_т = D_o = 335 мм имеем
S

=S_o/

=2/

=2/1,82=1,1 мм При D_т = D_и = 100 мм S

=S

=2 мм
Таким образом сокращение диаметра фланца с D_o = 335 мм до D_и = 100 мм и сопровождающееся при этом естественное утолщение этого фланца с S_дo=0,549 доS_ди= S_o , т.е. с S_дo=11мм до S_ди=2мм обеспечивает изготовление равностенной детали при заданных геометрических параметрах изделия.PRI me R. For drawing parts from aluminum alloy AMtsM (σ _in = 12 kgf / mm ² ), thickness S _o = 2 mm, diameter D _and = = 100 mm and depth H = 250 mm, first determine the diameter of the workpiece D _about (from the condition of equal metal volume before and after drawing):
π / 4 (D _o ² = D _and ² ) = π˙ D _and ˙Н whence
D _o =

=

=

= 335 mm
The current thickness S _t in the flange part of the workpiece is set according to the formula (1):
S _t = S

= 2

and when D _t = D _o = 335 mm we have
S

= S _o /

= 2 /

= 2 / 1.82 = 1.1 mm For D _t = D _and = 100 mm S

= S

= 2 mm
Thus reduction of the flange diameter D _o = 335 mm _and D = 100 mm, and accompanied with the natural thickening of the flange S = 0.549 _do doS _di = S _o, i.e. from S _to = 11mm to S _di = 2mm, it ensures the production of an equal-sized part with the given geometric parameters of the product.

Claims (1)

METHOD FOR DRAWING HOLLOW ITEMS FROM SHEET METAL, in which the reduction of the initial diameter of the workpiece is accompanied by deliberate corrugation and smoothing of the workpiece flange by applying the force from the punch side required for corrugation to the central part of the workpiece and the pressure from the side of the oscillating pressing characterized in that the hood with a reduction in the initial diameter of the workpiece is preceded by the hood of the product without reducing the initial diameter of the workpiece by rolling the fl Anza blanks until the formation of a variable thickness in it, the law of change of which is accepted according to the dependence
S _t = S

,
where S ₀ is the initial thickness of the workpiece;
S _t - the current thickness of the workpiece flange on a diameter of D _t ;
D _and - the outer diameter of the product being drawn;
D _t - the current diameter of the workpiece flange on which the thickness S _{t is set} .

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